﻿    <p>
      <em>IfcPropertyTableValue</em> is a property with a value range
      defined by a property object which has two lists of (numeric
      or descriptive) values assigned. The values specify a table
      with two columns. The defining values provide the first
      column and establish the scope for the defined values (the
      second column). An optional <em>Expression</em> attribute may
      give the equation used for deriving the range value, which is
      for information purposes only.
    </p>
    <p>
      The <em>IfcPropertyTableValue</em> defines a defining/defined
      property value combination for which the property name, the
      table with defining and defined values with measure type (and
      optional the units for defining and defined values) are
      given.
    </p>
    <blockquote class="note">
      NOTE&nbsp; The <em>IfcPropertyTableValue</em> only captures properties
      that can be expressed by a table with two columns. Use
      IfcPropertyReferenceValue with the PropertyReference being an
      IfcTable to express all those properties that require a table
      with tree or more columns.
    </blockquote>
    <p>
      The units are handled by the <em>DefiningUnit</em> and
      <em>DefinedUnit</em> attributes, see Table 2 for an example of a table value property:
    </p>
    <ul>
      <li>If the <em>DefiningUnit</em> or <em>DefinedUnit</em>
      attribute is not given, then the unit is already implied by
      the type of <em>IfcMeasureValue</em> or
      <em>IfcDerivedMeasureValue</em>. The associated unit can be
      found at the <em>IfcUnitAssignment</em> globally defined at the
      project level (<em>IfcProject.UnitsInContext</em>).
      </li>
      <li>If the <em>DefiningUnit</em> or <em>DefinedUnit</em>
      attribute is given, then the unit assigned by the unit
      attribute overrides the globally assigned unit.
      </li>
    </ul>
    <p>
      The <em>IfcPropertyTableValue</em> allows for the specification
      of a table of defining/defined value pairs of the property
      description. The optional attribute <em>CurveInterpolation</em>
      allows to determine the interval between two given values.
    </p>
<p>&nbsp;</p>
<table>
 <tr>
  <td>
   <table class="gridtable">
    <tr valign="top">
     <th align="left" valign="top" width="20%">Name</th>
     <th align="left" valign="top" width="10%">DefiningValues</th>
     <th align="left" valign="top" width="20%">DefiningValue Type<br> <span style="font-size:smaller">(through IfcValue)</span></th>
     <th align="left" valign="top" width="10%">DefinedValues</th>
     <th align="left" valign="top" width="20%">DefinedValue Type<br> <span style="font-size:smaller">(through IfcValue)</span></th>
     <th align="left" valign="top" width="10%">DefingUnit</b></th>
     <th align="left" valign="top" width="10%">DefinedUnit</th>
    </tr>
    <tr valign="top">
     <td>SoundTransmissionLoss</td>
     <td>100</td>
     <td><em>IfcFrequencyMeasure</em></td>
     <td>20</td>
     <td><em>IfcNumericMeasure</em></td>
     <td>-</td>
     <td>dB</td>
    </tr>
    <tr valign="top">
     <td>&nbsp;
          </td>
     <td>200
          </td>
     <td><em>IfcFrequencyMeasure</em>
          </td>
     <td>42
          </td>
     <td><em>IfcNumericMeasure</em>
          </td>
     <td>&nbsp;
          </td>
     <td>&nbsp;
          </td>
        </tr>
        <tr valign="top">
     <td>&nbsp;
          </td>
     <td>400
          </td>
     <td><em>IfcFrequencyMeasure</em>
          </td>
     <td>46
          </td>
     <td><em>IfcNumericMeasure</em>
          </td>
     <td>&nbsp;
          </td>
     <td>&nbsp;
          </td>
        </tr>
        <tr valign="top">
     <td>&nbsp;
          </td>
     <td>800
          </td>
     <td><em>IfcFrequencyMeasure</em>
          </td>
     <td>56
          </td>
     <td><em>IfcNumericMeasure</em>
          </td>
     <td>&nbsp;
          </td>
     <td>&nbsp;
          </td>
        </tr>
        <tr valign="top">
     <td>&nbsp;
          </td>
     <td>1600
          </td>
     <td><em>IfcFrequencyMeasure</em>
          </td>
     <td>60
          </td>
     <td><em>IfcNumericMeasure</em>
          </td>
     <td>&nbsp;
          </td>
     <td>&nbsp;
          </td>
        </tr>
        <tr valign="top">
     <td>&nbsp;
          </td>
     <td>3200
          </td>
     <td><em>IfcFrequencyMeasure</em>
          </td>
     <td>65
          </td>
     <td><em>IfcNumericMeasure</em>
          </td>
     <td>&nbsp;
          </td>
     <td>&nbsp;
          </td>
        </tr>
   </table>
  </td>
 </tr>
 <tr>
  <td><p class="table">Table 2 &mdash; Table value property with values, measure types and units</td>
 </tr>
</table>


    <blockquote class="history">
      HISTORY&nbsp; New entity in IFC2x.
    </blockquote>
    <blockquote class="change-ifc2x4">
      IFC4 CHANGE&nbsp; Attributes <em>DefiningValues</em> and
      <em>DefinedValues</em> have been made OPTIONAL with upward
      compatibility for file based exchange. The attribute
      <em>CurveInterpolation</em> has been added.
    </blockquote>
    <p>
      &nbsp;
    </p>
    <p class="spec-head">Informal Propositions:</p>
    <ol>
      <li>The list of <em>DefinedValues</em> and the list of
      <em>DefiningValues</em> are corresponding lists.
      </li>
    </ol>